The future of Windows XP
Q: “Why do you have to stop selling Windows XP?”
A: “We love that you love Windows XP. We've seen your passion on our website, in e-mails, and through independent online petition drives. Our engineers work hard to build innovative software that empowers our customers, so we're happy we made a difference.
The lifespan of every Microsoft product is carefully mapped from launch to retirement. Windows XP is no exception. We do this to ensure you always get the most out of your PC experience. Read about Windows lifecycle policy.
And another reminder; we're not "pulling the plug" on Windows XP. Although Windows XP won't be sold in stores, Microsoft and its partners will continue to offer technical support for Windows XP for months and years to come. In fact, Microsoft plans to support Windows XP until April 2014.
We're proud of Windows XP, a product that has empowered and entertained hundreds of millions of people in the last eight years. But technology doesn't stand still. And neither can we.”
http://www.microsoft.com/windows/windows-xp/future.aspx